"Our office analyzed the testimony that Mr. Gonzalez gave on those two days and we have come to the conclusion that he did not testify truthfully in compliance with the agreement," Ratner says in a letter to Salas.

Gonzalez signed an agreement with the district attorney to testify truthfully against Carrillo and Rodriguez. In exchange, he would be allowed to plead guilty to voluntary manslaughter, a lesser felony, and receive a 22-year sentence.

Rodriguez and Carrillo have a court hearing scheduled Wednesday. Ratner says in her letter to Salas that Gonzalez has an April 12 hearing.

During the investigation, Salas said, Gonzalez was interviewed many times and each time was pressed by Ratner for "more and more" details about the slaying.

"Finally, they get what they want, and they didn't want to use it," Salas said. "Without him, she is going to have problems getting convictions."

Rodriguez, of Santa Paula, and his cousin Carrillo, of Ventura, both 25, are charged with the gang-related drive-by killing of Edgar Flores, 27, in August 2007. Gonzalez drove the pickup used to commit the crime, according to court testimony.

In September, Ventura County Superior Court Judge James Cloninger declared a mistrial in the murder trial after jail phone conversations surfaced that raised questions about the credibility of Gonzalez. Gonzalez allegedly told people he had lied on the stand to get a plea bargain from the District Attorney's Office.

During the trial, three of Carrillo's former high school acquaintances who saw the shooting testified that Carrillo fired the gun. Gonzalez testified that Rodriguez was in the vehicle and handed a gun to Carrillo, according to court testimony.

In an interview, Rodriguez's lawyer, Ron Bamieh, said Salas told him during the trial that Ratner had threatened Gonzalez, telling Salas that unless Gonzalez "embellished" his testimony, the plea offer was off the table.

Salas said he will have to withdraw from representing Gonzalez because he might be called to testify about the conversation he had with Ratner.

Salas said he agreed to let Bamieh and his investigator interview Gonzalez. Salas said he told Bamieh that he had spoken with Ratner but never given Bamieh or his investigator details of that conversation.